A plurality of centrifuging steps are often performed in many microbiological and molecular-biological procedures, such as for instance DNA isolation. A container with a sample therein is centrifuged here in order to separate the solid constituents (referred to as pellet or debris) from the liquid (the supernatant). After the centrifugation the supernatant is removed from each container with sample. Because there are often tens of samples or more, this is very labour-intensive and requires a great deal of attention and, in addition, expensive plastic disposable materials such as pipette tips.